With the M'arrillians defeated, the Allied Tribes celebrate the new spirit of unity by staging a race through Perim. Though it's supposed to be a friendly competition, it quickly becomes clear that each Tribe wants one of their own Creatures to win... at any cost!

Confusion turns to shock for everyone when Krystella's "goody-goody" twin sister Jycella comes to Chaotic. And when their sibling rivalry erupts, Klay suggests a novel way of settling them: a Chaotic match.

After a seventh, hard-won battle in the Hotekk Drome, Tom gets the call he's been waiting for: it's CodeMaster Hotekk, challenging him to a CodeMaster Match.

When CodeMaster Hotekk's defeated Creatures join forces, it looks like Tom won't win his latest CodeMaster Match. But a shocking series of amazing events allows Tom and his friends to transport to a strange, primitive location that ultimately unlocks a secret that could change the course of Chaotic history.

Troubled that the leader of the Ancient OverWorld is an ancestor of Chaor, Tom goes to see Najarin to learn more about the history of Perim. Puzzled by Najarin's strange behavior, Tom returns to Ancient Kiru City to discover it has been attacked by Kaal, a diabolical UnderWorlder who holds the pre-historic Perimites in his fiery clutches.

Kaz decides to settle some old Chaotic scores by playing a series of grudge matches with his Ancient Creature scans. But his friends worry that he may accidentally reveal their secret portal to the past. Kaz's rematch marathon is super-successful until he challenges the sinister Sam Shady, who has a secret of his own!

Just as a massive monument to Chaor is about to be completed, Ulmar nervously gives the UnderWorld leader some shocking news: Ulmar has created a new army of gigantic robots called "Gigantropers." But his battling behemoths are out of control... and they're marching toward the Iron Pillar with a plan for devastation that even Chaor can't stop!

Now that the secret of Dranakis Threshold is out, Krystella and Klay devise a devilishly clever plan for making their Ancient Creature scans the ultimate collectors' items. To reach their goal, they call on the evil exiled rebel Van Bloot and, together, hatch a scheme that will make him the leader who seals Perim's fate for all time!

Peyton becomes embroiled in international intrigue when he's kidnapped by a mysterious agent who informs him that his Chaotic expertise is the only thing that can persuade a notorious art forger to work for the forces of good.

Kaz's obsession with scanning Kaizeph, the Lost City of the Elements, leads each of the four friends on a perilous, personal ScanQuest to capture the code of the mysterious "Elemental Servants." They ultimately face off in a four-way battle to determine which Elemental Creature can conquer all the rest.

Maxxor is confronted with the most agonizing decision of his life when Batog, an unstoppable creature out for vengeance, invades the OverWorld and presents an impossible demand: unless he battles Tangath Toborn, Perim will be destroyed. With Tangath still trapped in the ice at Glacier Plains, Maxxor must choose between his friend's life or his world's survival!